Don't let that limit you imagination though. think 2 animals like Tom&Jerry (some kind of interaction between them). A Battlemech chasing down a bug?

Another example:

Predatory birds (falcon?) have some attributes that might work well. It doesn't really make a difference whether you fly over land or over sea (-> cross platform), good perception (-> code clarity), good tactical overview due to height (-> not lowlevel), not constrained by gravity etc...

Suggestions do not require an example image or a detailed interpretation of the perks of an animal, but you should consider that people associate certain aspects with certain animals, which will affect how well the suggestion works.

Tbh I'm not sure. The image has 'vulture' in the name, so you're probably right. It was the first picture with suitable dimension that showed up on goggle picture search for "battlemech". I just needed something robot-like to make clear that it doesn't have to be an animal.

Today, I used some state diagrams at work for (software designing purposes), I immediately wanted to show you guys this one...
It's exactly what I think of OpenToolkit is, fun to use but serious at work.

About the graphic... Generally, it's a happy face, but how this graphic can be converted to something specific? Well it look like a bug to me (yikes :P !!! )... you can't change that :/ fame-is-fame. But you can go against this stereotype, you can propose that Open Source software is not buggy (at least for a period of time), it's organic, it's evolving continuously. So a bug for a mascot it's somehow an activist's perception of the software.

Alternatively, you can change this "happy" face to an octopus -we talked previously- and play safe and formal.

P.S. I just throw ideas on the table, do not judge me :). If you don't agree then ignore my message, just to prevent the conversation disorientation.
P.S.2 Not to mention historically that bugs were crawling inside computers... You know computers as large as buildings. ;)